Thermal insulation



L 19M. J. M. LE GRAN THERMAL INSULATION Fild March B, 1935 atented Vtien. 21, i941 attain i" STH .loseph M. lle wird.. eatvilie, `al,

of one-icuii to .lola l mond, va.

l l ndolpln Tucker, hic l Application Ill d, liti, herial No. tutti My invention relates eenerally to thermal in sulation and has to do more particularly with insulation structure including one or more etallic sheets so arraneed in a space as to insulate u aaainst the transfer oi heat therethroueh.

@ne oi the oloiects oi my invention is to provide an improved insuiat i structure oi the iore= soins character which is simple in construction, is easy and inensive to manufacture andiniu stall, and which insures high insulation emo-lenny at all times.'

other ohiect is to provide an insulation structure includins one or more metallic sheets iormed oi a material possession relatively lovr iii reuective characteristics when euposed to visihle radiation Vand relatively hielo. rehective chur-n acteristics when eiiposed to infrared radiation and vvhich is also adapted to resist the edects oi moisture (such as rusting and the litre) With- W out adectins its reflective characteristics.

il iurther ohiect is to provide an insulation structru'e pi the i'oreefoine` character comprising one or more comparatively stid" metallic sheets harina the sides thereoiD permanently coated with wit an alloy includine lead and tin and in `which at least seventy (lil) per cent lead is used.

@ther ohjects and advantaaes vrill heconie apparent iroin the following description, and hy reierence to the drawing wherein* 3@ Figure lis a horizontal section through a portion of a walled structure havine my linvention applied thereto;

his. 2 is a section taken substantially on line iwi oi his. l; and

35i itis. 3 is a separated perspective view of one oi the metallic insulation units shown in Figs. l and 2.

in the drawing, l have shown my invention applied to a structure that may well serve as a tu refrigerator cabinet; however, it is to be understood that this invention is applicable to all forms oi structure in connection with which similar thermal insulation conditions are to he met.

'ihe cabinet structure shown in Fiss. l and 2 is includes an inner `aall it and an outer Wall ll supported in any desired fashion by upright mud meschers it and horizontal members I3. "the Walls li and il and their supporting memhers may he formed of any suitable material.

uit The support members l2 and li are formed, preiru'alolyw however., from some suitable noncouductins material so as to minimize the transfer oi heat at that point hy conduction. By arranging the walls and their supports in the manner stated.,

au i provide wail spaces it to he insulated apainst j i. isa-sii the transier oi heat therethrough hy radiation, convection, and conduction. e structure for accomplishing such insulation will now he descrihed.

.iin insulatina unit Vit (lille. il is inserted in a each space. -unlt preierahly takes the outline shape oi the space it and it is comprised oi" a peripheral trame memher it oi such sine and shape as to ertend around and alone the walls denn the top, hottomv and ends oi the space it. io 'ihe trae it may he toed oi y suitahle mater-iai vine some neuihility d which ay he preiormed to serve as 'ar support lor a plurality or metallic sheets il and it. e trame member' it is normally ol slightly sreater Width, 4or depth, ld than the space it so that, when it is inserted within such space, its side crises it nrmiy and yieldahly ip the inner and outer Walls it and li so that the unit it as a vrhole is retained in place asainst vihrational strains and stresses and im shoclrs.

".l'he metallic sheets l'l and it may he iormecl oi any suitable material oi soient thickness and stiuness to retain preformed shape. iner-- pensive iron or steel sheets may vvell serve the purpose. rlhe sheets l'l and it are covered throughout with a metallic coating adapted to .resist the ehects oi isture, such as rusting and the like, which coatina provides the sheets with siu'faces possessing relatively low reflective char- 30 acteristics when esed to visible radiation (radiation of Wave lengths Within the visible portion oi' the electromagnetic spectrum) and relatively lush reflective characteristics when exposed to intra-red radiation (radiation of longer wave lengths than the visible portion of the electromaenetic sposti). lin usine the expressions relatively low and relatively high above, it is to he understood that this may mean low and high relative to each other, or low and high rela- 40 tive to material such as aluminum or other bright surfaced materials or coatings. More particularly, the sheets il and it are provided with a permanent coating in the form oi" an alloy consistina oi lead and tin. This alloy contains a is greater percentage of lead than tin, and not less than seventy per cent of lead. I have found that excellent results mar be obtained by using an alloy consisting of eighty-five lto eightyseven (87) per cent lead and thirteen (13) to 50 fifteen (15) per cent tin, in which case the sur faces of the sheets not only resist the eii'ect of moisture but they have the reilective characteristics above stated. The coating may be applied to the sheets at any desired stage ci 65 manufacture and in any suitable manner as, for example, by passing the same through a molten bath consisting of the requisite proportions of lead and tin. Such sheet iron coated with an alloy of tin and lead is known as terneplate.

Sheets l1 and I8 are supported by the frame member I6 at their edges only. To this end, the frame member I6 is provided with grooves I9 in which the edges of the sheets are snugly received and secured. In the use of this form of support, the sheets divide the space I4 into a plurality of substantially parallel spaces 20, 2I and 22 that are unobstructed throughout and are substantially sealed apart from each other by the frame member I6.

The sheets I1 and I8 may be spaced with respect to each other and to the walls I0 and II in any desired manner to suit the particular conditions of use. However, where adaptable, I prefer to space these sheets in the manner disclosed in my prior Patent No. 1,910,703.

It is believed that the operation of my invention will be readily understood from the foregoing. In' the use of my invention I have found that insulation against the transfer of heat by radiation and/or convection and/or conduction is minimized to a highly eiiicient extent; and that, also, when the metallic sheets I1 and I8 are exposed to moisture, they resist rusting and other detrimental effects so that the structure is capable of constant and indefinite use with substantially uniform insulation eiiiciency.

It will be appreciated from the foregoing that, while I have shown only one form of structure embodying my invention, changes in details and arrangement of parts may be made without departing from the spirit and scope of my invention as defined by the claims that follow. For example, thernumber of sheets employed in each unit may be varied. One or more may be used. The sheets may be spaced by any suitable form of frame member which is adapted to hold the sheets firmly in the proper spaced relation, which frame member passes only around the periphery of such sheets so as to leave the spaces dened thereby unobstructed substantially throughout. Also, the sheets I1 and I8 may have their surfaces ,divided into a plurality of angular and intersecting plane surfaces 23 as shown in Fig. 3, or they may be plain sheets with smooth surfaces.

I claim: l

1. In structure of the class described, means forming a space to be insulated, and means for insulating said space comprising at least one metallic sheet mounted in said space in spaced relation to said space forming means and forming a plurality of disconnected spaces, said sheet having its surfaces that are exposed to said spaces covered with a metallic coating formed of lead and tin, a greater proportion of lead being employed and to an extent suicient to provide a surface having relatively low reflective characteristics when exposed to visible radiation and relatively high reective characteristics when exposed to infra-red radiation together with mois:- ture resisting characteristics, and means for mounting said sheet in said space without obstructing said spaces in any substantial manner.

2. In structure ofthe class described, the combination of spaced walls deiining a space to be insulated, a plurality of metallic sheets mounted in said space in spaced relation with respect to each other and to said walls, said sheets being formed of a material of suilicient thickness and stiffness to retain preformed shape and being coated with an alloy consisting of not less than 70 per cent lead and the remainder tin providing a surface having relatively low reiiective characteristics when exposed to visible radiation and relatively high reiiective characteristics when exposed to infra-red radiation, and means for supporting said sheets in said spaced relation and whereby said space is divided intoa plurality of spaces substantially sealed apart from each other.

3. In structure of the class described, the combination with spaced walls defining a space to be insulated, of insulation means mounted in said space including a plurality of commercial black steel sheets of substantially the length and width of said space mounted therein in spaced relation with respect to each other and to said walls, said sheets having suicient stiffness to retain preformed shape and having a rustproof surface of high heat reflectivity by being permanently coated with an alloy formed of at least '15 per cent lead and the remainder including tin, and means iormounting said. sheets in said space in said spaced relation.'

4. .In combination, a pair of spaced walls and thermal insulation therebetween, said insulationl including a metallic sheet having suilicient stifi'- ness to retain pre-formed shape anda dull dark surface having high heat reflectivity, and means for spacing the insulation sheet from both said walls, said means including a member partly surrounding the edge surfaces of the insulation sheet and having its opposed edges resiliently engage the wall surfaces and be held thereby.

5. In a heat insulation unit, a sheet of terneplate of suflicient thickness and stiiness to retain preformed shape.

6. In structure of the class described, means forming a space to be insulated and means for insulating said space comprising a sheet of terneplate mounted therein with the spacing provided by said forming means being on opposite sides of said sheet. l

'1. A unit for use in heat insulating structures, comprising a metallic sheet having its surfaces covered with a metallic coating formed vof. lead and tin, the greater proportion thereof being lead, and means for securing said sheet in place in a space to be insulated, said means including laterally iianged portions extending from said sheet adjacent the ends thereof.

8. In a heat insulation unit, a body of supporting material of suiiicient thickness and stiliness to retain preformed shape and a layer supported by said body comprising an alloy of lead and tin, the lead content of said alloy being at least 70% thereof, said layer providing relatively low reflective characteristics when exposed to radiation of wave lengths within the visible portion of the spectrum and relative high reflective characteristics when exposed to radiation of wave lengths longer than those within the visible portion of the spectrum.

JOSEPH M. LE GRAND. 

